Adaptive Equipment problems of the 2007 Toyota Sienna

The rear hatch will close hard by its self on me or anyone else who is trying to load the back of the Sienna. This has happened several time over the years. Toyota fixed the problem at least twice, but the condition continues to occur. If I had a small child in my arms or my pet dog they would be injured as the hatch door closes on its own. The door alarm sounds and the hatch closes within a few seconds of opening it. It is difficult to override the automatic closing by keeping the hatch open by hand. It is almost impossible to use the hatch especially in the winter when the temperature is below 50 degrees.